Fits the 10 Frame Langstroth hives and seamlessly integrate with all Harvest Lane Honey bottom boards. With a small and medium gap, the reducer can be used to completely close off your hive for transport or as a protection from pesticide spraying. Reducers are also used to reduce the entrance of a hive during new package introduction or to prevent the hive from having to much cold air during winter. Standard usage is one reducer per hive.